Intercom network and terminal therefor

ABSTRACT

The invention relates to, among others, an intercom network ( 10 ), comprising a plurality of speech stations ( 11   a,    11   b,    11   c ) and at least one switching center ( 13, 16 ), wherein from each speech station connected to the switching center a connecting line ( 12   a,    12   b,    12   c ) extend to the switching center, wherein the connecting line provides a direct connection, respectively, between the switching center and the connected speech station, and wherein the speech stations of the intercom network, due to an audio data communication via the switching center, can enter into audio communication in real time. The particular feature consists, among others, in that at least one speech station ( 11   a ) comprises a terminal ( 53, 54 ) for a second connecting line ( 50, 50   a,    50   b,    50   c ), via which the speech station is connected with the same switching center ( 13 ) or with another switching center ( 16 ).

The applicant has been engaged in developing, producing and marketingintercom networks and speech stations for intercom networks for morethan 10 years.

A speech station in terms of the present patent application, in theinterest of a consistent nomenclature also in respect of the state ofthe art, is an element which comprises a loudspeaker and a microphoneand is configured for subscribing to an intercom network.

An intercom network is a kind of complex intercom system with numeroussubscribers. Speech data and signaling data or control data arecommunicated via the lines of the intercom network.

Intercom networks as currently known comprise a plurality of speechstations which are connected with each other via a switching center. Theconnections between individual subscribers, so-called speech stations,and the switching center are each configured as a direct connectionbetween the switching center and the connected speech station. Inparticular they are configured as hard-wired point-to-point connections.

For completeness' sake it is mentioned here that in addition tohard-wired point-to-point connections logical direct connections mayalso be provided. A logical direct connection of this kind betweenswitching center and speech station may be created, for example, in thata joint line section extends as far as a branching point and at thatpoint divides into two arms or branches, which lead to individual speechstations. Here, by means of network administration of this Y-shapedconnecting line, a logical direct point-to-point connection is createdbetween the individual speech station and the switching center. Theswitching center switches, configures and manages these connections. Assuch the switching center can, for example, ensure that certain speechstations can communicate directly with other certain speech stations orthat a speech station, after pressing a selection key, can communicatedirectly with another selected speech station.

The switching center is, so-to-speak, the switching mechanism of theintercom network, which configures all connecting paths.

At the speech station a plurality of selection keys is provided. Inconsequence to pressing a certain selection key, both the speech signalinput directly at this speech station and a signaling or control signalcommunicating to the switching center the information, which selectionkey has been pressed at this speech station, are transmitted via thepoint-to-point connection. The signaling or control signal may thereforecomprise a selection-key identification signal.

Upon receipt and in the knowledge of this selection-key identificationsignal the switching center can assign the audio signal received fromthis speech station to a target speech station and forward this to thesame.

There exists also the possibility that the audio signals input at thespeech station are forwarded simultaneously to several other speechstations. Vice-versa it is possible that audio signals aresimultaneously collected from several speech stations and are forwarded,superimposed, to one or more target speech stations. The typical namefor the latter is “group call”.

Generic intercom networks are used in broadcasting stations ortelevision stations. In addition they are used in theaters and at eventssuch as sports events or musical events or at any kind of event, wherelive reporting is employed.

State-of-the-art intercom networks are regularly configured as closedsystems. A generic intercom network comprises at least one switchingcenter and several speech stations. Another name for switching center is“matrix”.

Generic state-of-the-art intercom networks are, in particular,constructed using a star-shaped network architecture. This means thatall connecting lines extend in a star-shaped manner as hard-wiredpoint-to-point lines from a switching center to individual subscribers.

It is, however, also known to configure intercom networks, whichcomprise two or more switching centers. Here, in particular star-shapedconnecting lines extend from each switching center as hard-wiredpoint-to-point lines to individual connected speech stations. Theseveral switching centers are directly connected with each other. Eachspeech station, however, is connected to only one switching center.

Audio communication of one speech station connected to a first switchingcenter with another speech station connected to another switching centeris always realized in such a way that the audio signals are communicatedvia both switching centers. Such a system architecture of an intercomnetwork, with regard to the associated administrative effort, isfeasible only in certain cases of application.

A communication between speech stations of different switching centers,given the case that the switching centers assigned to the speechstations are not connected with each other, is not possible.

There exists a need, in intercom networks of the generic kind that incertain application situations, an operator of a speech stationconnected to a first switching center wants to enter into directcommunication with an operator of a speech station connected to a secondswitching center.

The invention is based on the requirement to provide an intercom networkwhich makes a communication of this kind possible.

The requirement is met according to the invention by the characteristicsof claim 1.

According to the invention an intercom network is provided, where atleast one speech station comprises a terminal for a second connectingline.

The first connecting line is the connecting line via which the speechstation is connected with the switching center.

Via the second connecting line the speech station is connected with thesame switching center or with another switching center.

Given the case that the speech station is connected with the sameswitching center via the first and the second connecting line, thereexists the possibility, according to the invention to provide anentirely redundant intercom network. This means an increase inreliability.

In case the speech station is connected with a first switching centervia the first connecting line and with a second switching center of thesame intercom network or another intercom network via the secondconnecting line, a considerable improvement of the application situationcan be achieved. For example this opens up the possibility for remoteapplications. On the other hand subscribers to the intercom network,i.e. operators of a speech station can work and communicatesimultaneously in different intercom networks.

For example it is possible for two transmission vehicles to transmit twodifferent football matches. A subscriber working at a speech station canbe connected with switching centers in the two different transmissionvehicles. Thus for example, one commentator can report on both matchesin succession.

The second connecting line is preferably provided as a direct hard-wiredpoint-to-point connection.

As explained in the beginning, the second connecting line may beprovided, exactly as the first connecting line, but also as a logicaldirect point-to-point connection between the speech station and the oneor more connected switching centers.

In particular, according to one embodiment, the invention allowsdifferent speech stations, which are connected to different switchingcenters, to directly communicate with each other.

The principle of the invention consists in connecting speech stationsvia the second connecting line, which is configured separately from thefirst connecting line, with one switching center. The speech station maythus be redundantly connected twice with the same switching center, ormay be connected with two different switching centers.

Management and administration of the terminals of the speech stations isperformed from that switching center, with which the speech station isconnected via the corresponding connecting line. In particular, giventhe case that a speech station is connected with two switching centers,management of the terminal for the first connecting line may be effectedby the first switching center, and management of the terminal for thesecond connecting line may be effected by the second switching center.

The second connecting line, in the same way as the first connectingline, may be any kind of line which permits the communication of audiodata. The first or second connecting line may, for example, be atelephone line or an internet line, in particular using a VoIP protocol.

According to the invention the second connecting line allows a speechstation to have a wide-area connection to two different switchingcenters. A wide-area connection is, in particular, considered to be one,where the two switching centers connected to the speech station arearranged remote from each other over great distances, in particular overdistances of more than 1 km, further in particular of more than 5 km.

The invention also covers the case where status signals are communicatedfrom the speech station to the two connected switching centers via thefirst and/or the second connecting line. For example, as the speechstation is switched on, information may be communicated to the connectedswitching center, regarding the type of operating mode in which thespeech station currently is or whether it is currently conducting acommunication via the first connecting line or via the second connectingline.

Insofar information on a standby mode, for example, may be communicatedfrom a speech station to the respective switching center connected tothe speech station, and managed by the switching center. Such standbyinformation may be communicated, for example, to all other operators ofspeech stations connected with the one or other switching center,thereby allowing all subscribers to obtain knowledge of the fact thatthe operator of this particular speech station is available to beapproached.

The two switching centers connected to the speech station can thereforekeep track of which speech stations they are currently connected to,which is their current operating mode and which is their currentoperator. With a variant of the invention provision may also be made fora first switching center connected with the speech station to receiveinformation from the speech station regarding with which other switchingcenter this speech station is connected via the second connecting line.

It is also possible, for example, to enter the name of an operator viathe speech station and to forward this to the two switching centersconnected with this speech station, and for the switching centers tomanage this.

Covered by the invention are those intercom networks, where theconnecting lines from one switching center extend to individual speechstations as direct, hard-wired point-to-point connections, whichinsofar, in particular, results in a star-shaped line architecture. Inaddition the invention also covers intercom networks, where first andsecond connecting lines extend from one switching center to individualspeech stations.

Advantageously provision is made for the invention to make it possiblefor an operator of a speech station, with the aid of a display at thespeech station or a display associated with the speech station, toreceive information for example, as to whether a certain subscriberpresent at a speech station connected to a switching center is currentlyavailable.

In terms of the invention this makes it possible, for example duringlive events, where quick consultations with other operators of speechstations connected to another switching center, are highly desirable,for an operator of a speech station to simply and quickly consult inthis way with an operator at another speech station.

The invention enables the speech station, which is connected with thefirst switching center, to communicate with all subscribers connected tothis switching center, and at the same time to communicate via thesecond connecting line with all subscribers, which are connected to thesecond switching center.

Each speech station comprises a loudspeaker and a microphone. Themicrophone is used to feed audio data into the network via an operator.The loudspeaker enables the operator at the speech station to outputreceived audio data.

According to an advantageous development of the invention each speechstation comprises selection keys, wherein when a selection key ispressed by the operator, an immediate audio connection can beestablished via the switching center between this speech station and aspeech station of the intercom network selected by pressing theselection key. The speech station therefore comprises several options inorder to connect this speech station with other speech stations of thisintercom network by simply pressing the selection keys.

It should be pointed out here that each speech station is alwaysconnected, via the respective connecting line, with only one switchingcenter. A point-to-point connection, in terms of hard-wiring, or also interms of a direct connection permits safe communication of a speechstation directly with another speech station via the switching center. Aspeech station, insofar as permitted by the switching center, cansimultaneously communicate with two or more other speech stations.

A speech station preferably comprises several selection keys similar todirect dialing buttons. The electrical lines associated with individualselection keys converge in a common line, i.e. the connecting line.Strictly speaking the several selection keys are connected in common tothe terminal arranged at the subscriber, for the connecting line.

According to the invention the speech station has a first group ofselection keys similar to direct dialing buttons arranged on it, whichconverge in a first connecting line, and a second group of selectionkeys similar to direct dialing buttons arranged on it, which converge ina second connecting line.

The switching center is able to recognize, via signaling data, i.e. thepreviously mentioned selection-key identification signal, which of theseveral selection keys has been pressed by the operator at the speechstation, and can establish the desired interconnection.

According to an advantageous development of the invention the speechstation comprises a connecting-line selection key. When theconnecting-line selection key is pressed by an operator a direct audioconnection can be established between the speech station and a selectedspeech station via the first or the second connecting line depending onwhich line was selected. In case the two connecting lines are connectedwith different switching centers, pressing the correspondingconnecting-line selection key allows access to either a plurality ofspeech stations connected to the first switching center or a pluralityof speech stations connected to the second switching center.

According to an advantageous development of the invention each speechstation comprises a display on which information can be displayed, whichis received by the speech station via the first connecting line and/orvia the second connecting line from the respectively connected switchingcenter. For example this may include the information, which speechstations are currently connected to the network or to the respectiveswitching center, or which switching centers are currently connected tothe speech station, or which operators are currently online or areavailable.

It is sufficient, however, if such a display is associated with thespeech station. For example, the display may be provided by a smartphone which may be connected, albeit only temporarily, to the speechstation.

Further advantageously, provision is made for each speech station tocomprise a user interface, i.e. an interface which allows the input ofinformation by the operator of the speech station for the purpose offorwarding this via the first connecting line and/or the secondconnecting line to the respectively connected switching center. An inputof information is understood, in particular, to be a possible selectionof information which has been made available by the respectivelyconnected switching center.

According to a further advantageous development of the invention thespeech station comprises a first connecting line terminal and a secondconnecting line terminal. The first connecting line terminal and thesecond connecting line terminal may be configured as physical terminals.

In case of a physical configuration of the first connecting lineterminal and/or the second connecting line terminal this means that aspecial connector, in particular a plug connector, for example a BNCconnector or another plug connector is provided here. The second plugconnector terminal is configured so as to be bodily or physicallyseparate or configured apart from the first connecting line terminal.

In case of an alternative development of the invention the connectingline terminal is configured as a logical terminal. By logical terminalis understood that a separate line path is provided within the speechstation, for example a path to a management component, which permitscommunication of this speech station via the second connecting line withthe same or with a further switching center.

With this variant of the invention a speech station is provided merelywith a single corporal or physical terminal, i.e. for connecting thespeech station with only one connecting line.

According to a further aspect of the invention the requirement consistsin proposing a speech station which is suitable for use in anabove-described intercom network.

This requirement is met according to the invention by thecharacteristics of claim 14.

Starting from a speech station of the generic kind, the characteristicaccording to the invention consists in that the speech station accordingto the invention, in addition to a first terminal for connection to afirst switching center, comprises a second terminal for connection to asecond switching center via a second connecting line or for connectionto the same switching center via a second connecting line, which isindependent of the first connecting line.

The second connecting line terminal arranged at the speech station maybe configured as a physical, i.e. bodily present terminal, for examplein terms of a plug connector or a plug or a socket. Such a bodilypresent terminal may be provided separately or apart from the alsobodily present or physical first terminal at the speech station forconnecting the speech station with the switching center via the firstconnecting line.

However, the invention also covers the alternative of a secondconnecting line terminal being present in the speech station accordingto the invention, which is configured as a logical terminal. Thislogical terminal may be provided due to internal circuitry or wiringpresent inside the speech station.

The logical terminal may comprise a physical connection, i.e. a cableconnection or circuit-based connection, to the bodily present secondconnecting line between the speech station and the second switchingcenter.

In other respects, as regards the advantages of individual features, andin order to avoid repetitions, reference should be made to theabove-mentioned remarks regarding an intercom network according to theinvention.

It should be noted at this point that the selection keys, as known fromthe state of the art, can be configured to be programmable. With othervariants of the invention the key pads of the selection keys can belabeled.

According to an advantageous development of the invention the speechstation has a display associated with it. Further advantageously such adisplay is arranged at the speech station.

The display may for example be provided by a separate device connectedonly temporarily with the speech station. The information shown on thedisplay may be information received by the speech station via the secondconnecting line.

The displayed information may for example include information regardinga notification, which speech stations are connected with the network orwhich speech stations are ready to communicate.

According to a further advantageous development of the inventionprovision may be made for the speech station to have a displayassociated with it, on which information can be displayed, which thespeech station receives via the first connecting line and/or via thesecond connecting line.

According to a further advantageous development of the invention thespeech station has a user interface associated with it. This can be usedby an operator for the input of information. This information may forexample refer to the communication via the second connecting line. Forexample, a name of an operator may be entered at the speech station. Thename entered may then be communicated to other speech stations via thesecond connecting line. In this way operators of other speech stationsknow that a certain operator of this interface is currently connectedand is ready to communicate, for example.

Advantageously the speech station comprises such a user interfacedirectly. In this case the user interface is arranged at the speechstation. The user interface may for example permit the entry of a numbercode. But the user interface may also be an alphanumeric user interface,a touch screen or similar.

According to a further advantageous development of the inventionprovision is made for the speech station to be associated with a userinterface, in particular for the user interface to comprise a userinterface which permits the input of information by an operator, inparticular the input of information of a selection of availableinformation by an operator, for example for the purpose of communicatingthe information via the first connecting line and/or via the secondconnecting line.

According to a further advantageous development of the invention thespeech station comprises an indicator which can signal to the operatorof the speech station the current operating mode of the speech station.For example, the indicator can indicate to the operator that theoperator is currently in communication with a further speech station viathe first connecting line or via the second connecting line or iscurrently in standby mode for communication with a network organized bya first switching center or with a network organized by a secondswitching center.

According to a further advantageous development of the inventionprovision is made for the speech station to comprise an indicator, whichindicates, as an operating mode, to an operator of the speech stationthat this speech station is in communication or ready to communicatewith, a further speech station via the first connecting line and/or viathe second connecting line.

Further advantages of the invention are revealed in the sub-claims notcited as well as in the below description of exemplary embodimentsillustrated in the figures, in which

FIG. 1 shows a schematic block-diagram-type view of a first intercomnetwork and a second state-of-the-art intercom network,

FIG. 2 shows a first exemplary embodiment comparable to FIG. 1, of anintercom network according to the invention, wherein a speech station isconnected with a first switching center via a first connecting line andwith a second switching center via a second connecting line,

FIG. 3, in a representation according to FIG. 2, shows a furtherexemplary embodiment of an intercom network according to the invention,where the two switching centers are also directly connected with eachother,

FIG. 4 shows a further exemplary embodiment of an intercom networkaccording to the invention in a representation according to FIG. 2,wherein the speech stations connected to the first switching center areeach connected via the first connecting line and via the secondconnecting line with the same switching center for providing a redundantintercom network,

FIG. 5 shows a further exemplary embodiment of an intercom networkaccording to the invention similar to the exemplary embodiment of FIG.2, wherein here, in contrast to FIG. 2, no physical first connectingline terminal and a second physical connecting line terminal aparttherefrom are provided, but where the second connecting line terminal isconfigured as a logical terminal,

FIG. 6 shows, in a schematic front view, a first exemplary embodiment ofa speech station according to the invention,

FIG. 7 shows a rear view of the speech station in FIG. 6 schematicallydrawn with two separate physical terminals, i.e. a first connecting lineterminal and second connecting line terminal configured apart therefrom,both of them configured as physical terminals,

FIG. 8 a further exemplary embodiment of a speech station according tothe invention in a representation according to FIG. 7, wherein here thesecond connecting line terminal is configured as a logical terminal, and

FIG. 9 shows a further exemplary embodiment of an intercom networkaccording to the invention in a representation according to FIG. 4,wherein this intercom network is configured so as to be fully redundant.

Exemplary embodiments are described by way of example in the figuredescription below, also with reference to the figures. For clarity'ssake, including insofar as different exemplary embodiments areconcerned, identical or comparable parts or elements or areas have beenmarked with the same reference symbols, partially with the addition ofsmall letters.

Features which have been described with reference to only one exemplaryembodiment, may, in terms of the invention, be provided also in anyother embodiment of the invention. Exemplary embodiments altered in thisway, even although not depicted in the drawings, are also covered by theinvention.

All disclosed features are, seen on their own, essential to theinvention. The disclosure of the application hereby covers, in full, thedisclosure content of the associated priority documents (copy of theprior application) as well as that of the cited publications of thestate of the art, also for the purpose of including individual orseveral features of these documents in one or in several claims of thepresent invention.

As regards the illustration of a state-of-the-art intercom networkaccording to FIG. 1, the parts or elements also present in exemplaryembodiments of the invention are marked there with an additionalapostrophe.

Initially, an intercom network 10′ according to the state of the art isexplained with reference to FIG. 1.

FIG. 1 shows a first intercom network 10′ according to the state of theart, and a second intercom network 14′ according to the state of theart.

The first intercom network 10′ comprises a switching center 13′, whichis shown, by way of example, to have three subscribers in the form ofspeech stations 11 a′, 11 b′ and 11 c′ connected to it. Each of thespeech stations is connected to the switching center 13′ via a firstconnecting line 12 a′, 12 b′, 12 c′, based on a star-shaped networkarchitecture.

The switching center 13′, so to speak, represents a center of thisintercom network 10′.

The connection between respective speech stations 11 a′, 11 b′ and 11 c′and the switching center 13′, in this exemplary embodiment, is realizedwith the aid of an, in particular, hard-wired point-to-point connection.This ensures high operational safety.

Configuration and switching of these point-to-point connections isperformed in the switching center 13′.

Each of the speech stations 11 a′, 11 b′ and 11 c′ comprises amicrophone and a loudspeaker.

Besides provision is made at each speech station for several selectionkeys, which allow an operator of the respective speech station toestablish an audio connection directly with another speech station. Thefirst intercom network is marked with 10′.

Moreover FIG. 1 shows a second intercom network marked with 14′.

This network again comprises a switching center 16′ and, shown by way ofexample, three speech stations 15 a′, 15 b′, 15 c′, which in turn areconnected with the switching center 16′ via in particular hard-wiredpoint-to-point connecting lines 17 a′, 17 b′, 17 c′.

It could for example be imagined that the first intercom network 10′ isassociated with a first broadcasting station and the second intercomnetwork 14′ is associated with a second broadcasting station.

There is no way in which these two different intercom networks 10′, 14′of the state of the art, can communicate with each other. In particular,a user of a speech station, for example speech station 11 a′ of thefirst intercom network 10′, cannot establish a connection with a speechstation of the second intercom network 14′.

It shall now be explained by way of the first exemplary embodiment ofthe invention according to FIG. 2, how a speech station 11 a isconnected via a first connecting line 12 a with a first switching center13 of a first intercom network 10, and via a second connecting line 50with a second switching center 16 of a second intercom network 14.

The speech station 11 a according to the invention may be part, both ofthe first intercom network 10 managed by the first switching center 13and part of the second intercom network 14 managed by the secondswitching center 16.

The speech station 11 a can thus communicate, via the first connectingline 12 a, with all subscribers 11 b and 11 c connected to the firstswitching center 13, and can communicate, via the second connecting line50, with all subscribers 15 a, 15 b, 15 c connected to the secondswitching center 16.

According to FIG. 2 the intercom network 10 according to the inventioncomprises a first speech station 11 a, a second speech station 11 b anda third speech station 11 c. The number of speech stations is arbitraryand depends on the type and use of the respective intercom network 10.

The speech stations are respectively connected, via first connectinglines 12 a, 12 b, 12 c, with the switching center 13 of the firstintercom network 10.

Again, the point-to-point connections are hard-wired connections, whichensure high operational safety. Respective management and switching iscarried out in the switching center 13. Also, some configuration iscarried out in the switching center 13, which for example determines,which of the individual speech stations 11 a, 11 b, 11 c connected tothe switching center 13 can at all establish a communication with whichone or ones of the one or more remaining speech stations 11 a, 11 b, 11c.

The second intercom network 14 of the exemplary embodiment of theinvention according to FIG. 2 comprises a switching center 16, withwhich speech stations 15 a, 15 b, 15 c are connected via the connectinglines 17 a, 17 b, 17 c.

Each of the speech stations shown in FIG. 2 by way of example may beprovided by a speech station to be described later in more detail withreference to FIGS. 6 to 8.

The speech station 11 a of the first intercom network 10, in contrast tothe speech station 11 a′ according to the state of the art of FIG. 1,comprises a first connecting line terminal 52 and additionally a secondconnecting line terminal 53.

Via the first connecting line terminal 52 the speech station 11 a can beconnected via the first connecting line 12 a with the switching center13. Via the second connecting line terminal 53 the speech station 11 acan be connected via the second connecting line 50 with the secondswitching center 16.

The first connecting line 12 a and the second connecting line 50 areboth realized as a point-to-point connection permitting directcommunication.

Based on this network architecture the user of the speech station 11 aof the intercom network 10 is able to get into direct contact with theoperator of a speech station of both intercom networks 10 and 14, evenduring operation of the intercom network 10. On the other hand, insofaras allowed by the respective switching center 13, 16, each subscriber toboth intercom networks 10, 14 is able to enter into communication withthe subscriber of the speech station 11 a.

Assuming that for example the first intercom network 10 is associatedwith a first broadcasting station and is used to accompany, for example,a football match in terms of a live transmission, and assuming that thesecond intercom network 14 is used, for example at the same point intime, by another broadcasting station, in order to accompany anothersports event, the following situation may arise:

The user of the speech station 11 a may for example be in need ofrequesting information about a certain image setting option. Further hemay have information that a user of the speech station 15 c of thesecond intercom network 14 is approachable at this point in time and isable to divulge this information.

The user is now able to directly access the speech station 15 c via thesecond connecting line 50 and the second switching center 16, in orderto establish a direct audio communication with this speech station 15 c.In this way, due to the operator of the speech station 11 a being ableto talk to the operator of the speech station 15 c, the missinginformation can be quickly communicated.

On the one hand the audio data communicated from a first speech station11 a to another speech station 15 c includes pure speech information.

On the other hand signaling or control data may be communicated whichallows the switching mechanism to identify the selected selection keysin terms of a target button.

In addition control data may also be communicated via the firstconnecting lines 12 or via the second connecting lines 50, and thiscontrol data may for example represent a switch-on or switch-off commandfor a lamp or another electrical device.

A further exemplary embodiment of the invention is explained withreference to FIG. 3. This is different from the exemplary embodimentshown in FIG. 2 only in that the two switching centers 13, 16 aredirectly connected with each other via a switching center connectingline 51. This embodiment takes into consideration that intercom networks10 of the inventive kind can also be developed in such a way thatseveral switching centers 13, 16 are provided and are directly connectedwith each other.

A further exemplary embodiment of an intercom network 10 according tothe invention is shown in FIG. 4. Here only one switching center 13 isprovided which for example has three speech stations 11 a, 11 b, 11 cconnected to it.

Each speech station 11 a, 11 b, 11 c is connected with the switchingcenter 13 via a first connecting line 12 a, 12 b, 12 c.

Each of the three speech stations 11 a, 11 b, 11 c is, however, alsoadditionally connected via a second physical terminal 53 and a secondconnecting line 50 a, 50 b, 50 c with the same switching center 13.

In this way it is possible to provide a redundantly configured intercomnetwork 10.

Finally FIG. 5 shows a further exemplary embodiment of an intercomnetwork 10 according to the invention. Here, in contrast to the previousexemplary embodiments, provision is made, not for two separate physicalterminals 52, 53, as shown in FIG. 4, but here the second physicalterminal 53 is configured as a logical second terminal 54 for connectingthe respective speech station 11 a with the second connecting line 50.

According to FIG. 5 the invention also covers the case, where theterminal 53 for connecting to the second connecting line 50 a isconfigured as a logical terminal 54, which is connected, via an internalline 31 or a corresponding switching path via a so-called logicalterminal point 33, with the connecting line 12 a.

The second connecting line 50 branches off from the connecting line 12 ain the area of a branch-off point 32. The branch-off point 32 representsa line split and can be arranged at any suitable point between thespeech station 11 a and the first switching center 13.

The expert, however, will realize that an appropriateswitching-technical connection can be provided also at any other speechstations (e.g. speech station 11 c or speech station 15 c) of thisembodiment or other embodiments.

Exemplary embodiments of speech stations configured in accordance withthe invention will now be explained, and these can be employed in anintercom network 10, 14 according to the invention. Then follows anexplanation of how information is communicated from the server to theoperators of individual interfaces.

Referring to FIG. 6 an exemplary embodiment of a speech station 11according to the invention is constructed in an essentially conventionalmanner. The speech station 11 is shown in a front view.

The loudspeaker 20 and a microphone 21 are shown on the left-hand side.

The speech station 11 comprises, in a manner known as such, a pluralityof selection keys 22 a, 22 b, 22 c, 22 d, 22 e, 22 f, 22 g, 22 h, theexact number of which is arbitrary. By means of these selection keys theoperator of the speech station 11 can, by actuating a certain selectionkey, establish a direct speak/listen connection to another speechstation. This connection is established via the in particular hard-wiredpoint-to-point connecting lines 12 a, 12 b, 12 c, 12 d, 17 a, 17 b, 17c, 17 d, 50, 50 a, 50 b, 50 c and the corresponding switching center 13,16.

Each speech station can establish a direct intercom connection withanother selected speech station. Group calls are also possible, forexample, a speech station can establish a simultaneous intercomconnection with a plurality of other speech stations.

The speech station 11 according to FIG. 6 of the invention, in contrastto state-of-the-art speech stations, additionally comprises a selectionkey 23, which enables the speech station 11 to gain direct access to thespeech station of another intercom network 14.

The selection key 23 can be used to select either of the two switchingcenters 13, 16. Alternatively it may be used to select one of the twoconnecting lines 12 a, 50.

The selection key 23 has been depicted merely as an example.

It is left to the expert to find a concrete solution for this.

In other embodiments of the invention the respective speech station isnot provided with such a selection key. Here internal circuitry is usedto directly establish a connection with the corresponding counterpartupon pressing one or more selection keys such as selection keys 22 a, 22b, 22 c, 22 d, 22 e, without the need to select a switching center 13,16 or a connecting line 12 a, 50.

In addition the speech station 11 in FIG. 6 comprises an optionalindicator 27, which signals to the operator of this speech station 11that the speech station is in a certain operating mode, e.g. in one ofseveral possible operating modes. For example the indicator may signalto the operator that the speech station is currently in a firstoperating mode, in which it communicates via the switching center 13, orthat it is in a second operating mode, in which it communicates via theswitching center 16.

The schematically shown indicator 27 may also be configured as atouchscreen and insofar, represents a user interface or an access 28,which offers the option as to whether a communication shall beestablished with a first switching center 13 or a second switchingcenter 16, or whether a communication shall take place with other speechstations via a first connecting line 12 or a second connecting line 50.

In FIG. 6, the element marked with 28 may also be configuredadditionally and/or alternatively as a user interface or interface or asaccess 28.

The invention also covers the case where a first group of selection keys(e.g. selection keys 22 a, 22 b, 22 c, 22 d) permits communication ofthis speech station via the first connecting line 12, and a second groupof selection keys (22 e, 22 f, 22 g, 22 h) permits communication of thisspeech station with other speech stations via the second connecting line50.

Alternatively or simultaneously the operator of this speech station maybe notified via the indicator 27, with which intercom network 10, 14 thespeech station 11 is currently communicating, or which subscribers arecurrently accessible from this speech station.

FIG. 7 shows in a schematic rear view that the speech station 11according to the invention comprises a first terminal 52 for connectionwith the first switching center 13 via the first connecting line 12, anda second terminal 53 for connection with the second switching center 16via the second connecting line 50. With this embodiment the firstconnecting line terminal 52 and the second connecting line terminal 53are configured as physical terminals separate from each other. They mayfor example be plug connectors.

By contrast the further exemplary embodiment of an interface 11 in arear view as per FIG. 8 only shows a first physical terminal 52 forconnection with the first connecting line, wherein the second terminal53 for connection with the second connecting line is configured as alogical terminal 54 and is connected, analogously to the diagram of theembodiment in FIG. 5, via an internal line 31 with the first connectingline terminal 52.

It should be noted that the number of speech stations and the number ofswitching centers, which can be connected to one speech station or thenumber of connecting line terminals, which can be provided at one speechstation, can be selected freely at random in all embodiments.

FIG. 9 shows a still further exemplary embodiment of an intercom network10 according to the invention, which is configured to be entirelyredundant. The layout and architecture of this intercom network 10according to the invention is comparable to the layout of the embodimentof FIG. 4. The difference compared to FIG. 4 consists in that here theintercom network comprises two switching centers 13, 16. One of the twoswitching centers, for example switching center 13, normally operates onits own. It is only if the switching center 13 fails, that the secondswitching center 16 takes over. To this end the two switching centers13, 16 are configured so as to be identical, so-to-speak mirrored, asthe expert would say.

Each of the speech stations 11 a, 11 b, 11 c is connected via theassociated first connecting line 12 a, 12 b, 12 c with the firstswitching center 13. At the same time, each of the speech station 11 a,11 b, 11 c is connected via a second connecting line 50 a, 50 b, 50 cwith the second switching center 16, provided as a redundant switchingcenter.

Given the case that the switching center 13 fails during operation ofthe network, for example during a live event, the second switchingcenter 16 can immediately take over the work and function of the failedfirst switching center 13 without the operator or the user of speechstations 11 a, 11 b, 11 c noticing or having to notice anything, andkeep the operation of the intercom network going.

The two identically configured switching centers 13, 16 may be connectedwith each other, something which is not shown in FIG. 9. Such aconnection may, for example, include constantly checking the functionsof the first switching center 13, and/or permit the transmission of afault signal or an initialization signal which commands the secondswitching center 16 to immediately switch on and take over operation, ifthe first switching center 13 fails.

In other respects the embodiment shown in FIG. 9 corresponds to theabove description of the remaining embodiments, therefore in order toavoid repetition reference should be made to the above passages.

With the embodiment shown in FIG. 9 provision may also be made, forexample, for the two switching centers 13, 16 to take over operation inturn regularly, without a failure having been diagnosed. For example,provision may be made that at regular time intervals, say every 60seconds for example, one of the two switching centers 13, 16 takes overfrom the other switching center 16, 13, thereby ensuring alternateoperation.

The deciding factor is, however, that the intercom network 10 accordingto FIG. 9 allows for alternate operation, so that an intact, mirroredswitching center 16, with the aid of a plurality of second connectinglines 50 a, 50 b, 50 c is able to fully take over operation in case of afault or failure of the first switching center 13.

Each of the speech stations 11 a, 11 b, 11 c comprises, as is evidentfrom FIG. 9, a terminal 52 a, 52 b, 52 c for connection with the firstconnecting line 12 a, 12 b, 12 c, and a second terminal 53 a, 53 b, 53 cfor connection with the second connecting line 50 a, 50 b, 50 c.

As a matter of form it should be added that again two separate physicalterminals or two separate terminals 52, 53 may be used, where the secondterminal 53 may be alternatively configured as a logical terminal 54,which however is not shown in FIG. 9.

1. An intercom network, comprising a plurality of speech stations and atleast one switching center, wherein from each speech station connectedto the switching center a connecting line extends to the switchingcenter, wherein the connecting line provides a direct connection,respectively, between the switching center and the connected speechstation, and wherein the speech stations of the intercom network, due toan audio data communication via the switching center, can enter intoaudio to communication with each other in real time, wherein at leastone speech station comprises a terminal for a second connecting line,via which the speech station is connected with the same switching centeror with another switching center.
 2. The intercom network according toclaim 1, wherein the speech station connected with the same switchingcenter via the second connecting line, providing a redundant connectingline compared to the first connecting line.
 3. The intercom networkaccording to claim 2, wherein each of the speech stations connected to aswitching center comprises a terminal for a second connecting line, viawhich the speech station is connected with the same switching center,thereby forming a redundant intercom network.
 4. The intercom networkaccording to claim 1, wherein the speech station is connected via thesecond connecting line with another switching center of the sameintercom network.
 5. The intercom network according to claim 1, whereinthe speech station is connected via the second connecting line withanother switching center of another intercom network.
 6. The intercomnetwork according to claim 1, wherein each speech station comprises aloudspeaker and a microphone.
 7. The intercom network according to claim1, wherein each speech station comprises several selections keys,wherein when a first selection key is pressed by an operator, a directaudio connection can be established between this speech station and aselected speech station via the first connecting line and via a firstswitching center, and when a second selection key is pressed by anoperator, a direct audio connection can be established between thisspeech station and a selected speech station via a second connectingline and the second switching center.
 8. The intercom network accordingto claim 1, wherein, when a first selection key is pressed by anoperator, a direct audio connection can be established between thisspeech station and a selected speech station via the first connectingline, and when a second selection key is pressed by an operator, adirection audio connection can be established between this speechstation and a selected speech station via the second connecting line. 9.The intercom network according to claim 1, wherein a speech stationcomprises an access for selecting a connection via the first connectingline or the second connecting line, wherein via the access, inparticular when a connecting-line selection key is pressed by anoperator, a direct audio connection can be established between thisspeech station and a further selected speech station either via thefirst connecting line or via the second connecting line.
 10. Theintercom network according to claim 1, wherein a speech station has adisplay associated with it, in particular in that a speech stationcomprises a display, on which information can be displayed regardingwhich connecting line has been selected or is active or regarding whichswitching center has been selected or is active.
 11. The intercomnetwork according to claim 1, wherein a speech station comprises a userinterface, which permits the input of information by an operator, inparticular a selection of available information by an operator, for thepurpose of communicating the information via the first connecting lineor via the second connecting line.
 12. The intercom network according toclaim 1, wherein the terminal for connecting the speech station via asecond connecting line with a switching center is configured as aphysical terminal, and is made separately available by a firstconnecting-line terminal arranged at the speech station.
 13. Theintercom network according to claim 1, wherein the terminal forconnecting the speech station via a second connecting line with aswitching center is configured as a logical terminal, wherein thelogical terminal is connected with a second connecting line.
 14. Aspeech station for use in an intercom network comprising at least oneswitching center, with a loudspeaker and a microphone, and a firstconnecting line terminal for connection with the switching center, andwith several selection keys, wherein, when a selection key is pressed byan operator, a direct audio connection can be established between thisspeech station and a selected speech station of the intercom network viathe switching center, wherein the speech station comprises a secondconnecting line terminal for connecting the speech station via a secondconnecting line with the same switching center or for connecting thespeech station with another switching center.
 15. The speech stationaccording to claim 14, wherein the speech station comprises an access tothe second connecting line, in particular a connecting-line selectionkey, wherein due to pressing the access, in particular when theconnecting-line selection key is pressed by an operator, a direct audioconnection can be established between this speech station and a furtherselected speech station, optionally via the second connecting line.